Best Pick
eBay Brand Central14.5" x 18.5" Polyjacket/Polymailer — 400 Envelopes
14.5″ × 18.5″ × 0″
+$0.00 Seller Free shipping · 3 lb billed
$0.290
landed per box
pack of 400 · $116.00
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⚠ DIM +17 lb100% Perfect fitBuy →
⚠ DIM +17 lb100% Perfect fitBuy →
⚠ DIM +17 lb100% Perfect fitBuy →
⚠ DIM +17 lb100% Perfect fitBuy →
⚠ DIM +17 lb100% Perfect fitBuy →
Cheapest 18×14×12 padded mailer
Compare real eBay prices for 18×14×12 shipping boxes with DIM-weight-aware shipping estimates.
Live listings — sorted by landed cost per box
eBay Brand CentralBuy →
⚠ DIM +17 lb100% Perfect fitGRAINGER APPROVED 11A767 PK 25 Shipping Box,18x14x12 in 11A767
18″ × 14″ × 12″
+$9.99 Seller Calculated · 19 lb billed
$1.72
landed per box
$1.32 each
pack of 25 · $33.00
⚠ DIM +17 lb100% Perfect fit25 - Pack Medium Cardboard Moving Boxes 18x14x12 32 ECT With Handles
18″ × 14″ × 12″
+$0.00 Seller Free shipping · 19 lb billed
$1.88
landed per box
pack of 25 · $47.00
⚠ DIM +17 lb100% Perfect fit50 - 18 x 14 x 12 Corrugated Shipping Boxes Storage Cartons Moving Packing Box
18″ × 14″ × 12″
+$0.00 Seller Free shipping · 19 lb billed
$2.09
landed per box
pack of 50 · $104.50
⚠ DIM +17 lb100% Perfect fit18x14x12 Corrugated Shipping Boxes 25/pk
18″ × 14″ × 12″
+$0.00 Seller Free shipping · 19 lb billed
$2.24
landed per box
pack of 25 · $56.00
⚠ DIM +17 lb100% Perfect fit25 - 18 x 14 x 12 Corrugated Shipping Boxes Storage Cartons Moving Packing Box
18″ × 14″ × 12″
+$0.00 Seller Free shipping · 19 lb billed
$2.44
landed per box
pack of 25 · $61.00
Showing 6 of 29 real listings. Want all of them with custom quantity and weight? Search now →
What fits in a 18×14×12 box
A 18 × 14 × 12 inch box holds 3,024 cubic inches (1.75 cu ft) of interior space, putting it in the large-category. It's a popular choice for shipping items like multiple pairs of shoes, small appliances, clothing bundles — things that fit comfortably within those dimensions while leaving room for protective padding. Large boxes at this size are usually sold in smaller bulk packs — 10 to 25 — because storage and shipping of the empty stock itself becomes a consideration.
Shipping math for this size
Shipping cost for this size depends heavily on dimensional weight. For a 18×14×12 box, UPS and FedEx Ground compute a DIM weight of 22 lbs using their 139 divisor, while USPS Ground Advantage uses a 166 divisor, giving 19 lbs. Carriers bill whichever is greater — your actual weight or the DIM weight. USPS's higher divisor makes it roughly 3 lbs cheaper than UPS/FedEx for this size when your item is light, which is why our search results factor in DIM-weight automatically instead of just showing sticker prices.
How to pick the right pack size
When buying a 18×14×12 box, the biggest cost lever isn't which retailer you pick — it's which pack size you commit to. A 100-pack typically costs 2-3× more than a 25-pack but brings the per-unit cost down by 40-60%. Our ranking is based on **landed cost per box** — the pack price plus shipping, divided by the number of boxes. A 100-pack with $10 shipping works out cheaper per box than a 25-pack with the same shipping, because the fixed cost spreads further. Every listing below links to a real product page from eBay, ULINE, or other retailers; we don't show placeholder results.
Search with your own dimensions
Pre-filled with 18×14×12. Adjust weight, quantity, or size as needed — we'll re-rank for your exact scenario.